Abdul Abu-Mahmoud acquired a series of tattoos, before and after the shooting, including one saying "Revenge is a dish best served cold" and another in Arabic reading "eye for an eye, tooth for a tooth and blood for blood".

The 35-year-old pleaded not guilty in the NSW Supreme Court to murdering 15-year-old Brayden Dillon.

The teenager was slayed on Good Friday in 2017 at his Glenfield family home after his mother and stepfather were threatened with a gun.

Conrad Craig, 29, was jailed for at least 30 years in July for murder after admitting being the hooded gunman who burst into the teenager's room and shot him as he slept.

After a judge-alone trial, Justice Ian Harrison on Thursday found Abu-Mahmoud guilty of murder by organising the hit and paying Craig $20,000.

He also found him guilty of soliciting witness F to murder Brayden on an earlier occasion and soliciting witness A to murder his older brother Joshua Dillon.

His nephew Adam Abu-Mahmoud was stabbed to death in a Panania street brawl in July 2016.

Joshua Dillon was charged over the death, but was ultimately found not guilty by a jury in October last year.

Justice Harrison found the uncle began focusing on Brayden to avenge his nephew's death, after Joshua Dillon was kept in protective custody after his arrest over the street brawl.

He found Abu-Mahmoud made threats at three court appearances, including by telling Joshua Dillon: " You are dead. You are dead. Sign out of protection and come to area 5 in the main. I swear on the Koran you are dead."

He also threatened Joshua Dillon's father, saying "I am going to kill you or your son. No actually I am going to kill your whole f***ing family".

Craig, witness F and witness A were members of Brothers for Life, the notorious street gang founded by convicted criminal Bassam Hamzy.

But the judge said he couldn't find Abu-Mahmoud belonged to the gang.

At his trial, he pointed the finger at Hamzy as being the organiser of Brayden's murder submitting he directed all aspects of the gang's operations including killings.

But Justice Harrison said the suggestion "rises no higher than mere conjecture or supposition".

He also rejected a bid by Craig to change his story from what he originally told police about being directed and paid by Abu-Mahmoud to carry out the shooting.

He contradicted the agreed facts submitted for his murder sentencing, instead saying he either acted alone or upon instructions from Hamzy.

"I am in any event satisfied that Mr Craig's denials of the truth of his earlier versions of what occurred are false," the judge said.

Dubbed "revenge tatoos" by the Crown, the judge noted the extent and content of them are "indeed quite extraordinary" being a permanent statement of his desire for vengeance, as well as a statement that he achieved it.

"Mr Abu-Mahmoud's tattoos operate as a constant reminder to himself, and a perhaps unsubtle statement to those in his circle, that he should not be regarded as weak, or as only capable of doing financial errands for Bassam Hamzy."

.He adjourned the case to October 15 when a sentencing hearing date will be set.

Australian Associated Press